Novel Compositions Comprising Structural Isomers Of 1,4-Cyclohexanedimethanol Dibenzoate and Polymer Compositions Containing Same

ABSTRACT

Novel solid benzoate ester compositions are mixtures comprising the trans- and cis-structural isomers of 1,4-cyclohexanedimethanol dibenzoate wherein the trans isomer constitutes from 1 to 66 or from 72 to 99 weight percent of the mixture. The properties imparted to a variety of polymer compositions, including hot melt adhesives, cannot be achieved using the commercially available mixture of these isomers.

FIELD OF THE INVENTION

This invention relates to novel mixtures containing two structuralisomers of 1,4-cyclohexanedimethanol dibenzoate in controlled portions.More particularly this invention relates to a method for preparing theseisomeric mixtures and the use of these mixtures to impart desirableproperties to a variety of polymer compositions including but notlimited to hot melt adhesives.

DESCRIPTION OF THE PRIOR ART

The dibenzoate of 1,4-cyclohexanedimethanol, hereinafter referred to asCHDM, exists in two isomeric forms. One of these is a trans form thatcan be represented by the formula

The second is a cis form that can be represented by the formula

It has been found that the cyclohexane ring in both of these isomers isin the “chair” form to avoid steric interactions between the bulkymethylbenzoate groups.

One commercial process for preparing 1,4-cyclohexanedimethanol, thestarting material for preparing the dibenzoate, involves hydrogenationof 1,4-cyclohexanedicarboxylic acid or an ester of this acid to thecorresponding dialcohol. The isomeric distribution in the resultantmixture of cis and trans isomers is determined by the starting materialsand hydrogenation catalyst. U.S. Pat. No. 6,919,489, which issued toOrth et al. uses a Raney nickel catalyst doped with rhenium to obtainCHDM with a cis to trans ratio of 0.7 or less from the dimethyl ester ofthe corresponding dicarboxylic acid having a cis to trans ratio of 1.2to 2.1.

Other patents disclosing the ability to control the cis to trans ratioof CHDM by adjusting the conditions or molar ratio of hydrogen to adialkyl ester of 1,4-cyclohexanedicarboxylic acid include U.S. Pat. Nos.5,395,986 and 5,395,987.

Methods for separating the cis- and trans-stereoisomers of CHDM arereported in the literature. Malachowski et al (Ber. 1938, 71, 159accomplish this by reducing diethyl hexahydroterephthalate with sodiumand alcohol. From either the cis- or trans-hexahydro ester astereoisomeric mixture of the corresponding alcohol was obtained. Thecis- and trans esters in the mixture were separated by conversion to thecorresponding benzoates followed by fractional crystallization andhydrolysis.

The present invention is based on the discovery of a method forseparating a commercially available version of CHDM dibenzoatecontaining about 70 weight percent of the trans isomer and about 30weight percent of the cis isomer into fractions containing up to 100percent by weight of either isomer. Mixtures containing from 1 to 66weight percent or from 72 to 99 weight percent of the trans isomer havenot been reported in the literature and are therefore considered novelcompositions.

The present inventors have discovered that the properties imparted topolymer compositions, particularly hot melt adhesives, by the presentbenzoate ester mixtures will vary considerably depending upon therelative concentrations of trans and cis isomers in the mixture.

U.S. Pat. No. 5,026,756 to William D. Arendt discloses that thedistinguishing feature of the compound referred to in the patent as thedibenzoate of 1,4-cyclohexanedimethanol (hereinafter CHDMDB) relative toother esters of benzoic acid is the existence of a well-defined freezingpoint. When heated above their melting points and then allowed to coolto below this temperature most other dibenzoates will typically remainliquid at temperatures substantially below their melting points, aphenomenon referred to as “supercooling”.

The ability to reproducibly solidify makes the isomers of CHDMDBuniquely suitable for use in hot melt adhesives. The aforementionedArendt patent contains the curve produced when a sample of CHDMDB isheated in a differential scanning calorimeter. The curve is described asbimodal, with melting points at “about 80 and 123° C.” The highermelting point is more sharply defined.

The CHDMDB described in the aforementioned Arendt patent is preparedfrom a commercially available product containing about 68 weight percentof the trans isomer and about 32 weight percent of the cis-isomer ofCHDM.

The present invention is based on the discovery that when a mixture ofCHDMDB isomers referred to in the aforementioned Arendt patent is heatedabove its melting point and then gradually cooled, a partialsolidification in the form of a crystalline material occurs at atemperature of about 100° C. Analysis of this crystalline material bygas chromatography reveals that it is a mixture typically containingmore than 90 weight percent of the trans isomer. The remainder of themolten material solidifies below about 70° C. to a non-crystallinematerial containing approximately equal weights of the trans and cisisomers.

It has also now been found that the present trans- and cis-rich mixturesimpart different properties to polymer compositions in general and tohot melt adhesives in particular. By using one of the present CHDMDBmixtures containing more than about 72 percent by weight of the transisomer as a modifier both the open time and the time required for theadhesive to achieve its ultimate properties are substantially reducedrelative to the values obtained using the isomer distribution of theproduct described in the Arendt patent. The second of these advantagesallows for a substantial increase in the maximum speed of a productionline on which hot melt adhesives are used to bond two layers of paper,cardboard, fabric or other material. It was also found that adhesivescontaining a mixture with more than about 72 weight percent of the transisomer can be designed to be significantly stronger than adhesives basedon prior art modifiers.

Open time is the time interval during which the adhesive applied to thefirst substrate remains sufficiently adhesive to effect a bond betweenthis substrate and a second one applied to it. Set time is defined asthe time required for bonding once the two substrates to be joined arepressed together.

SUMMARY OF THE INVENTION

This invention provides novel solid benzoate ester compositionscontaining both the cis and trans isomers of 1,4-cyclohexane dimethanoldibenzoate wherein the trans isomer constitutes from 1 to 66 or from 72to 99 weight percent of the compositions. A preferred compositioncontains 90 to 94 weight percent of the trans isomer, and mostpreferably more than 95 weight percent of the trans isomer. In anotheraspect the composition includes 48 to 52 weight percent of the transisomer.

This invention also provides a method for separating a commerciallyavailable form of 1,4-cyclohexane dimethanol dibenzoate (CHDMDB) usingmelt refining into a crystalline solid composition containing from 72 toabout 99 weight percent of the trans isomer of 1,4-cyclohexanedimethanoldibenzoate and a partially crystalline solid containing from 1 up toabout 66 weight percent of this trans isomer.

A third aspect of the present invention provides a wide variety ofpolymer compositions containing any of the isomer mixtures of thisinvention as a plasticizer or other type of modifier. Depending upon thetype(s) of polymer(s) and other ingredients present, the estercompositions of this invention impart a variety of desirable propertiesto polymer compositions.

Hot melt adhesives constitute a preferred class of polymer compositionsof this invention. These compositions typically comprise 1) a polymertypically selected from the group consisting of olefinic polymers,including but not limited to ethylene/vinyl acetate copolymers andstyrene/olefin copolymers, 2) at least one hydrocarbon resin and 3) oneof the present CHDMDB isomer mixtures as a modifier.

Benzoate ester compositions of this invention containing more than about72 weight percent of the trans isomer of 1,4-cyclohexanedimethanoldibenzoate typically decrease set times and can increase bond strengthof hot melt adhesives, among other advantages. Ester compositions ofthis invention containing less than about 66 weight percent of thistrans isomer can increase open time of these adhesives in addition toproviding other advantages.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a DSC trace of commercially available CHDMDB, Benzoflex 352.

FIG. 2 is a DSC trace of trans rich CHDMDB, XP-7007.

FIG. 3 is a DSC trace of cis rich CHDMDB, XP-7008.

DETAILED DESCRIPTION OF THE INVENTION

The novel benzoate ester mixtures of this invention are prepared by meltrefining using the following series of process steps:

-   -   1. A commercially available mixture containing about 68 to about        70 weight percent of the trans and about 30 to about 32 weight        percent of the cis isomers of CHDMDB is heated to a temperature        above the melting point of the mixture to form a molten material        which is then allowed to gradually cool to about 100° C., at        which point crystallization of a portion of the material occurs.        The melting point will be in the range of about 120 to        about 128. The relative concentrations of trans and cis isomers        in the crystallized material will be determined by the rate of        cooling to the crystallization temperature and the time interval        during which the mixture of molten and crystalline materials is        maintained at this temperature. For example, cooling for 1 hour        resulted in formation of 84-86% trans isomer and cooling for 16        hours resulted in formation of 94-96% trans isomer.    -   2. The crystalline material containing up to 97 weight percent        of the trans isomer of CHDM dibenzoate is isolated from the        mixture.    -   3. The remaining liquid material is allowed to cool to ambient        temperature to obtain a solid containing substantially equal        weights of the trans and cis isomers.

The CHDMDB used as a starting material to obtain the isomeric mixturesof this invention can be prepared by reacting benzoic acid or a suitablederivative thereof with one of the commercially available forms of1,4-cyclohexanedimethanol. One such product contains about 70 weightpercent of the trans isomer and about 30 weight percent of the cisisomer. The resultant benzoate ester is commercially available asBenzoflex® 352.

Mixtures of CHDMDB isomers containing from 72 to 99 weight percent ofthe trans isomer are particularly suitable for use as modifiers in hotmelt adhesives based on the processing advantages of faster set timewith a sufficiently long open time relative to Benzoflex® 352. Data inthe accompanying examples demonstrate that these isomer mixtures alsoincrease the crystallization rate of the resin component of the adhesiveby up to two times relative to Benzoflex® 352 in addition to providingstronger bonds. In practical terms, this reduces the time required fordevelopment of maximum bond strength.

For applications requiring longer open times than that can be achievedusing the trans isomer rich fraction, CHDMDB mixtures containing morethan about 34 weight percent of the cis isomer will provide this longeropen time.

The types of polymers typically used in hot melt adhesives include butare not limited to ethylene/vinyl acetate copolymers, polyolefins, blockcopolymers based on styrene, acrylates and olefins, olefins based onmetallocene catalysts, amorphous polyalphaolefins, acrylic rubberincluding acrylic triblocks, ethylene/ethyl acrylate copolymers,polyurethanes of the reactive and non-reactive types, polyesters,sulfopolyesters and polyamides.

The types of tackifying resins used in hot melt adhesives include butare not limited to aliphatic resins, aromatic resins, pure monomerresins, mixed aromatic and aliphatic resins, rosins, rosin esters,terpene and other mixed monomer resins.

When the present CHDMDB isomer mixtures are used in a hot melt adhesive,the concentration range for these mixtures is from 2 to 50 weightpercent, preferably from 15 to 35 weight percent, based on the totalweight of the adhesive formulation. The optimum concentration isdetermined by a number of parameters, including but not limited todesired open and set times, melt viscosity, adhesion and strength.

Applications of hot melt adhesives include but are not limited toproduction of non-woven fabrics, packaging materials, product assembly,book binding adhesives, and adhering of labels. Composite articles mayinclude two bonded layers of materials selected from the groupconsisting of woven and non-woven fabrics, solid films and sheets formedfrom natural and synthetic polymers, packaging materials, glue sticks,construction materials, book bindings, and labels. Non-woven fabric mayinclude a diaper or feminine hygiene article. Bonding is achieved usinga molten adhesive composition that includes an organic polymer, a resinand a modifier selected from the group consisting of a first mixturecontaining more than 72 weight percent of the trans isomer of1,4-cyclohexanedimethanol dibenzoate, preferably 90-94 weight percent ofthe trans isomer, or a second mixture containing less than 66 weightpercent of the trans isomer of 1,4-cyclohexanedimethanol dibenzoate.

The CHDMDB compositions of this invention offer processing and/orproduct advantages relative to other types of plasticizers and modifiersin a variety of polymer compositions, including but not limited topowder coatings, waterborne coatings, hot melt coatings, solvent-basedcoatings, u.v. curable coatings, and inks of the jet such as hot meltjet ink, varnish such as overprint varnish, solution and water-bornetypes.

In this aspect, the benzoate compositions may include organic polymerand a modifier for said polymer. The modifier may include mixtures ofthe trans and cis isomers of 1,4-cyclohexane-dimethanol dibenzoate,where the trans isomer constitutes from 72 to 99 weight percent of thecomposition; or mixtures the isomers where the trans isomer constitutesfrom 1 to 66 weight percent of the composition. The composition may be aplastisol. The composition may be used in engineering plastics for thefabrication of articles by extrusion or injection molding. Further, thecomposition may include an organic or aqueous vehicle.

The present benzoate compositions act as a processing aid for a varietyof plastics, and as both a reinforcing filler and process aid inengineering plastics such as polycarbonates, polyphenylene oxide/styreneblends and similar polymers. As used herein, “processing aides” arematerials that can be added in small quantities (1-5%) whereuponsubstantial improvement results in the processing without significantdetraction from other properties. Abstracted from Encyclopedia of PVCVolume II, Page 602 Marcel Dekker, Inc, NY.

The following examples describe the preparation and evaluation of thepresent isomer mixtures of CHDMDB and should not be interpreted aslimiting the scope of the invention as defined in the accompanyingclaims. Unless otherwise specified all parts and percentages are byweight. Properties of the isomer mixtures and compositions containingthese mixtures were measured under ambient conditions.

EXAMPLE 1

This example describes the preparation of a CHDMDB isomer mixture of thepresent invention.

100 parts by weight of a CHDMDB isomer mixture containing about 70weight percent trans-CHDMDB and about 30 percent of the cis isomer,available as Benzoflex® 352 (hereinafter referred to as “control”), wereplaced in an oven heated to a temperature of 140° C. The temperature ofthe oven was then lowered to 100° C. and maintained at this temperaturefor 16 hours. The liquid portion of the composition was decanted,leaving a solid crystalline material. Analysis of the crystallinematerial by gas chromatography revealed a trans isomer content of 96percent. This material will be referred to hereinafter as XP-7007

The aforementioned liquid portion solidified at ambient temperature andwas found to contain about equal parts by weight of the cis and transisomers. This material will be referred to hereinafter as XP-7008.

All of the materials were analyzed using a TA model 2910 DSCdifferential scanning calorimeter. The resultant curves are representedin the accompanying drawings: FIG. 1 for the control, FIG. 2 for XP-7007and FIG. 3 for XP-7008. The peak for the crystalline XP 7008 materialoccurs at 80.2° C., considerably higher than the peaks for thecommercial ester mixture at 56.77° C. and the considerably broader peakfor XP-7008, which is indicative of a higher content of the cis isomer.

EXAMPLE 2

This example compares the effect on resin crystallization rates of thethree CHDMDB isomers of example 1. The five resins evaluated areconventionally used in hot melt adhesives and can be described asfollows:

Regelrez® 1094 (Resin A)—A pure monomer aliphatic resin available fromEastman Chemical

Wingtack® 95 (Resin B)—A C₅ aliphatic resin available from GoodyearChemical

Nevex® 100 (Resin C)—An aromatic resin available from Neville Chemical

Eastotac® H-100R (Resin D)—A hydrogenated aliphatic resin available fromEastman Chemical

Escorez® 5300 (Resin E)—A cycloaliphatic resin available from ExxonMobil Chemical Company

All samples contained 5 grams of the resin and 5 grams of the isomermixture.

Crystallization rates were determined using the following procedure: Thesamples were heated in an oven at 177° C. for 15 minutes, stirred andheated for an additional 15 minutes at the same temperature. The sampleswere then removed from the oven and allowed to crystallize. The timeintervals for initial and complete crystallization are recorded in Table1.

The isomer mixtures are identified as follows:

1=control=a commercially available mixture identified as Benzoflex® 352containing a tran:cis isomer weight ratio of 70:30

2=XP 7007 a mixture with a trans:cis weight ratio of 92:8

3=XP 7008 a mixture with a trans trans:cis weight ratio of 1:1

TABLE 1 Crystallization Isomer Time (minutes) Resin MixtureInitial/final A 1 2.25/11.5  A 2 1.0/8.5  A 3 4/31 B 1 1.9/15   B 21.0/9   B 3 6.2/28   C 1 9/55 C 2 4/35 D 1 3/23 D 2 2/12 E 1 4/25 E 22/14

The data in Table 1 demonstrate the accelerated rate of crystallizationachieved using isomer mixture 2 containing the highest concentration ofthe trans isomer. The rate of crystallization is retarded relative tothe control using the isomer with the highest cis isomer content, whichmay be desirable for some commercial applications.

EXAMPLE 3

This example compares the properties imparted to various formulations bythe benzoate isomer mixture of this invention with those imparted by aknown isomer mixture.

Preparation of Adhesive Formulations

All of the adhesive formulations were prepared by melting theingredients other than the polymer at 177° C. while mixing at low speed(400 RPM's). The polymer was then added in slowly and mixed untilhomogeneous, which required a maximum mixing time of 30 minutes. Ifdegassing was required, the adhesive formulation was placed in a can andheated for one hour in an oven.

Composition of Adhesive Formulations Formulation 1. A Block CopolymerConstruction Adhesive for Non-Woven Fabrics

50 parts of Regelrez® 1094—A pure monomer aliphatic resin available fromEastman Chemical

0.5 parts of Inorgox®1010—an antioxidant available from Ciba GeigyCorporation35 parts of the isomeric CHDMDB to be evaluated, identified as describedin Example 1.25 parts of Kraton® G-1652, a styrene/ethylene/butadiene/styrenecopolymer available from Kraton Polymers

Formulation 2. A Palletizing Adhesive

10 parts of an ethylene/vinyl acetate copolymer available as Elvax® 150from Dupont

50 parts of an aromatic resin available from Neville Chemical as Nexex®10050 parts of the CHDMBD isomer mixture to be evaluated1 part of Irganox® 1076,

Formulation 3. A Typical Glue Stick Formulation

25 parts of a 400 melt index ethylene/vinyl acetate copolymer containing28 mole percent of vinyl acetate, available as Elvax® 210 from Dupont

21 parts of 4 melt index ethylene/vinyl acetate copolymer containing 28mole percent of vinyl acetate, available as Elvax® 260 from Dupont35 parts of Sylvatac® 100NS, a rosin ester available from ArizonaChemical parts of the CHDMDB isomer mixture to be evaluated0.1 part of an antioxidant available as Irganox® 101 from Ciba GeigyCorporataion

Formulation 4. A Typical Label and Generic Packing Glue

25 parts Elvax® 210

25 parts of Sylvatac® 100 NS25 parts of the CHDMDB isomer0.1 part of an antioxidant available as Irganox® 1010 from Ciba Geigy3 parts of mineral oil available as Tufflo 6056 from Citco

Formulation 5. An Adhesive for Nonwoven Applications Based onMetallocene Polyolefins

37 parts of metallocene catalyzed polyolefin available asLicocene®PP2602 from Clariant

3 parts of metallocene catalyzed polyolefin available as Licocene®PE420120 parts of the CHDMDB isomer40 parts of cycloaliphatic resin available as Escorez® 5300 from ExxonMobil0.1 part of Irganox® 1010

Test Procedures

Average open times, based on a minimum of 3 measurements, weredetermined using 2 inch-wide strips of Kraft paper. The formulation tobe evaluated was heated to 177° C. in an oven. A 10 mil-thick film ofthe molten adhesive was applied to the paper strip using a 3 inch-longBird draw-down bar and a timer was started. A second strip of Kraftpaper was applied over the adhesive at the desired time interval using aback and forth stroke with a 50 gram wood block and immediately removed.This procedure was repeated at longer time intervals until nofiber-tearing bonds were observed. The time interval at which thisoccurred was recorded and appears in Table 2.

Average set times, based on a minimum of three measurements, weredetermined by applying the molten formulation being evaluated to a 3½inch wide strip of Kraft paper using a 3 inch-wide Bird draw down bar.The formulation had been heated to a temperature of 177° C. in an oven.A 10-mil thick film of the adhesive was applied to the paper strip usinga draw down bar and a second paper strip was applied followed by handpressure. The upper layer of paper was pulled away at a constant rate.The time interval at which tearing of the paper fiber was first observedwas noted and recorded as the set time. The set time values appear inTable 3.

Adhesion to a variety of substrates was determined by applying themolten formulation to a sheet of 110-pound lithographic paper andallowing the coating to solidify. The coated paper was cut into 2 by 2inch (5 cm. by 5 cm.) squares and the coated side applied to glass,white pigmented (W) or clear (C) PVC (polyvinyl chloride), steel,aluminum and oak. The coated paper was heated with a hot air blower toactivate the adhesive, following which the resultant composite wasallowed to cool. The cooled paper was pulled off the substrate and thepercentage of torn paper fibers was evaluated.

The temperature at which adhesion failed due to shearing forces (SAFT;shear adhesion fail temperature) was determined by applying a 6 milthick layer of the molten adhesive to be evaluated on to a piece ofMylar® film. When the adhesive cooled a 1-inch by 6-inch strip of thefilm was applied to a sheet of stainless steel to form a 1-inch by1-inch lap joint. The area of overlap was then heated with a hot air gunto melt the adhesive, forming the bond. The free end of the film stripwas attached to a one kilogram weight using a paper clip. The resultantcomposite was then attached to a support with sufficient clearance toallow the weight to fall. The assembly was then placed in an oven heatedto 50° C. The oven temperature was increased by 5° C. every half hour.The temperature at which the weight fell was noted.

The temperature of adhesion failure was determined for adhesiveformulation 2 (the palletizing adhesive) by application of a 3/16inch-diameter bead of this formulation to a 2″ by 16″ piece ofcorrugated cardboard. The adhesive was used to form a bonded laminatewith a 2″×2″ piece of laminated cardboard. At one-minute intervals thestrength of the bond was determined. The time required for complete bondfailure was recorded.

Melt viscosity values were obtained at 177° C. using a model DV II RVTBrookfield viscometer equipped with a Thermosel® apparatus and a number18 spindle rotating at a speed of 5 RPM was selected to determineapparent viscosity.

The results of the evaluations are recorded in the following tables. Thesamples of CHDMDB are identified as “Control” for the commercialmaterial, XP-007 for the mixture containing 96 percent of the transisomer and XP 008 for the material containing substantially equalweights of the trans and cis isomers.

Melt Viscosity (mPa·s) at 177° C.

TABLE 2 Formulation Control XP 7007 XP 7008 1 4819 3084 3402 2 467 204198 3 9177 9382 12680 4 358 140 435 5 1011 1100 7008

TABLE 3 Average Open Time Formulation Control XP 7007 XP 7008 1 107 s 23s 222 sec 2 3.8 m 1.2 m 9.6 min 3 4.5 m 2 m 12.6 m 4 <10 s <5 sec <10 s5 60 s 60 s 96 s s = seconds m = minutes

TABLE 4 Average Set Time (Seconds) Formulation Control XP 7007 XP 7008 14 2 5 3 16 15 21 4 3 <3 4 5 23 25 23

TABLE 5 Adhesion Formula- tion Substrate Control XP 7007 XP 7008 1 A100% fiber tear 100% fiber tear 100% fiber tear 3 B 100% fiber tear 100%fiber tear 100% fiber tear C 100% fiber tear 50% fiber tear 100% fibertear D 100% fiber tear 100% fiber tear 100% fiber tear F 100% fiber tear100% fiber tear 100% fiber tear G 100% fiber tear 100% fiber tear 100%fiber tear H 100% fiber tear 90% fiber tear 60% fiber tear 4 B Heavyfiber Small degree of 50% fiber displacement, fiber tearing no transferdisplacement; No tearing Substrates: A = diaper stock; B = glass; C =white PVC; D = clear PVC; E = steel; F = aluminum; G = oak

TABLE 6 Temperature of Adhesion Failure Due To Shearing Forces (SAFT) (°C.) Formulation Control XP 7007 XP 7008 1 60° 75° 60° 3 60° 60° 55°

TABLE 7 Time Interval To Adhesion Failure of Palletizing AdhesiveFormulation 2 Control XP 7007 XP 7008 2 4 minutes <1 minute 8 minutes

1. A composition comprising trans and cis isomers of1,4-cyclohexane-dimethanol dibenzoate wherein the trans isomerconstitutes from 72 to 99 weight percent of said composition.
 2. Acomposition according to claim 1 wherein the trans isomer is from 90 to94 weight percent of said composition, and the composition has a meltingpoint of 120 to 128° C.
 3. A composition comprising trans and cisisomers of 1,4-cyclohexane-dimethanol dibenzoate, wherein the transisomer is from 1 to 66 weight percent of said composition.
 4. Acomposition according to claim 3 wherein the trans isomer is from 48 to52 weight percent of said composition and the melting point of saidcomposition is from 80 to 84° C.
 5. A method for preparing a solidcomposition comprising cis- and trans-isomers of1,4-cyclohexanedimethanol dibenzoate and containing more than 72 weightpercent of said trans isomer, said method comprising 1) heating to aboveits melting point a composition comprising 68-70 weight percent of thetrans isomer and 30 to 32 weight percent of said cis isomer for a timeinterval sufficient to form a molten material; 2) allowing said moltenmaterial to cool to 100° C. and maintaining this temperature for aperiod of time effective to crystallize and isolate a solidifiedcomposition containing said trans isomer, and 3) allowing the remainingportion of said molten composition to solidify.
 6. A method according toclaim 5 wherein the concentration of said trans isomer is increased byincreasing the time period for crystallization.
 7. A hot melt adhesivecomposition comprising a a) at least one polymer selected from the groupconsisting of ethylene/vinyl acetate copolymers, polyolefins, blockcopolymers based on styrene, acrylates and olefins, olefins based onmetallocene catalysts, amorphous polyalphaolefins, acrylic rubberincluding acrylic triblocks, ethylene/ethyl acrylate copolymers,polyurethanes of the reactive and non-reactive types, polyesters,sulfopolyesters and polyamides; b) a tackifying resin selected form thegroup consisting of aliphatic resins, aromatic resins, pure monomerresins, cycloaliphatic resins, rosin, resin esters, terpene and mixedmonomer resins, c) an antioxidant and d) a modifier composition selectedfrom the group consisting of (1) mixtures of trans and cis isomers of1,4-cyclohexane-dimethanol dibenzoate wherein the trans isomerconstitutes from 72 to 99 weight percent of said composition, and (2)mixtures of trans and cis isomers of 1,4-cyclohexane-dimethanoldibenzoate wherein the trans isomer constitutes from 1 to 66 weightpercent of said solid composition.
 8. A method for accelerating a settime and crystallization rate of a hot melt adhesive compositioncomprising a thermoplastic polymer, a resin and a modifier, said methodcomprising selecting as said modifier a blend of structural isomers of1,4-dimethyl-cyclohexyl dibenzoate containing at least 72 weight percenttrans isomer.
 9. A method according to claim 8 wherein saidthermoplastic polymer is selected form the group consisting ofethylene/vinyl acetate copolymers, polyolefins, metallocene-catalyzedolefin polymers, amorphous polyolefins, block copolymers based onstyrene acrylates and olefins, ethylene/ethyl acrylate copolymers,polyurethanes of the reactive and non-reactive types, polyesters,sulfopolyesters, acrylic block and triblock copolymers, acrylicelastomers and polyamides, and the tackifying resin is selected from thegroup consisting of aliphatic, cycloaliphatic and aromatic resins, puremonomer resins, functional resins, and terpene resins, and said blendcontains 90 to 94 weight percent of said trans isomer.
 10. A compositearticle comprising two bonded layers of materials selected from thegroup consisting of woven and non-woven fabrics, and solid films andsheets formed from natural and synthetic polymers, wherein the bondinghas been achieved using a molten adhesive composition comprising anorganic polymer, a resin and a modifier selected from the groupconsisting of a first mixture containing more than 72 weight percent ofthe trans isomer of 1,4-cyclohexanedimethanol dibenzoate.
 11. Acomposite article according to claim 10 wherein said article is selectedfrom the group consisting of non-woven fabrics, packaging materials,glue sticks, construction materials, book bindings and labels.
 12. Acomposite article according to claim 11 wherein said non-woven fabric isa diaper or a feminine hygiene article.
 13. A composition comprising anorganic polymer and a modifier for said polymer, wherein said modifieris selected from the group consisting of (1) mixtures comprising thetrans and cis isomers of 1,4-cyclohexane-dimethanol dibenzoate whereinthe trans isomer constitutes from 72 to 99 weight percent of saidcomposition; and (2) mixtures comprising the said isomers wherein thetrans isomer constitutes from 1 to 66 weight percent of said coatingcomposition.
 14. A composition according to claim 13 wherein saidcomposition is a plastisol.
 15. A composition according to claim 13wherein said polymer is selected from the group consisting ofengineering plastics for the fabrication of articles by extrusion orinjection molding.
 16. A composition according to claim 13 wherein saidcomposition further comprises an organic or aqueous vehicle.
 17. Acomposition according to claim 13 wherein said composition is selectedfrom the group consisting of coatings, inks, varnishes, and roomtemperature activated adhesives.
 18. A composition according to claim 17wherein said coating is a powder coating and said ink is a hot melt jetink and said varnish is an overprint varnish.
 19. A compositionaccording to claim 13 wherein said modifier is a process aid for saidpolymer.
 20. A method according to claim 8 wherein said thermoplasticpolymer is selected form the group consisting of ethylene/vinyl acetatecopolymers, polyolefins, metallocene-catalyzed olefin polymers,amorphous polyolefins, block copolymers based on styrene acrylates andolefins, ethylene/ethyl acrylate copolymers, polyurethanes of thereactive and non-reactive types, polyesters, sulfopolyesters, acrylicblock and triblock copolymers, acrylic elastomers and polyamides, andthe tackifying resin is selected from the group consisting of aliphatic,cycloaliphatic and aromatic resins, pure monomer resins, functionalresins, and terpene resins, and said blend contains 48-52 weight percentof said trans isomer.
 21. A composite article comprising two bondedlayers of materials selected from the group consisting of woven andnon-woven fabrics, and solid films and sheets formed from natural andsynthetic polymers, wherein the bonding has been achieved using a moltenadhesive composition comprising an organic polymer, a resin and amodifier selected from the group consisting of a first mixturecontaining less than 66 weight percent of the trans isomer of1,4-cyclohexanedimethanol dibenzoate
 22. A composite article accordingto claim 19 wherein said article is selected from the group consistingof non-woven fabrics, packaging materials, glue sticks, constructionmaterials, book bindings and labels.
 23. A composite article accordingto claim 20 wherein said non-woven fabric is a diaper or a femininehygiene article.